Elongated sheet base materials made of resin have flexibility and good processability, and is accordingly publicly known to be used to fabricate electronic parts or optical components by the steps of forming a predetermined thin film such as a predetermined metal or oxide film on surfaces of the elongated sheet base materials, performing heat treatment or plasma processing thereof, and the like. Depending on the use of an elongated sheet base material, the same predetermined processing may be performed on both of the front and back surfaces of the sheet base material.
As an apparatus for performing predetermined processing on both of the front and back surfaces of such a sheet base material, there has been kwon an apparatus in which a first processing chamber and a second processing chamber are both provided in continuation with a transportation chamber including a feed roller, a take-up roller, and transporting means for feeding and transporting a sheet base material. The first processing chamber includes a processing means for performing predetermined processing on one surface (front surface) of the sheet base material, and the second processing chamber includes another processing means for performing the same processing as the foregoing on the other surface (back surface) of the sheet base material having the one surface already subjected to the processing (e.g., see Patent Document 1).
However, in the above-described apparatus of the known example, since the front and back surfaces of the sheet base material are processed in the separate processing chambers, the system itself becomes large in size, and also requires a large number of parts, which leads to high cost. Further, the productivity is low since the apparatus has a long path along which the sheet base material fed from the feed roller is passed through the two vacuum processing chambers and is then wound around the take-up roller.